WASHINGTON -- House Republican leaders are zeroing in on the package of massive spending cuts and reforms they plan to attach to next month’s vote to raise the debt limit.

The pieces being considered for the package include a mix of hard discretionary spending caps, substantial cuts to mandatory spending, a reduction in federal government hires and a fail-safe “trigger” option that would force additional cuts if Medicaid reforms or spending cuts are not enacted by a certain date.

A House GOP leadership aide told The Huffington Post on Wednesday that the package is “not final by any stretch,” but that its key pieces are coming into focus.

The aide gave some specifics: a provision related to federal government attrition, which would limit one government hire for every two that retire, is already looking "likely." On the trigger, the senior staffer said Republicans are planning to put forward a "more effective" option than what was proposed by the Senate's "Gang of Six,” the bipartisan group hammering out a deal on deficit reduction. As for spending cuts, expect the kinds of discretionary spending caps and “real” cuts to mandatory spending outlined in the House GOP budget put forward by Budget Chairman Paul Ryan (R-Wis.), added the aide. That proposal lays out $6.2 trillion in cuts over the next decade.

“We will make clear that real, actual cuts that get enacted into law are required -- not the promise of future cuts by a future Congress,” said the leadership aide. “Anything else is a non-starter.”

The Obama administration has yet to signal real support for tying spending cuts to a vote on the debt limit, although the two will almost certainly be paired in order to secure GOP votes for raising the debt ceiling. The U.S. will reach its congressional-imposed $14.29 trillion borrowing limit by May 16 unless lawmakers act before then.

At Tuesday’s White House briefing, Press Secretary Jay Carney, seemingly unprompted, touted the president’s preference for a fail-safe trigger over hard caps on spending or a balanced budget amendment. When asked by The Huffington Post on Wednesday whether Obama would be comfortable with the proposal being tied to the debt limit vote, Carney reiterated that it would be dangerous to "hold hostage" such a vote "to any other piece of legislation.”

Pressed further, he refused to discuss ongoing discussions. “I'm not negotiating individual pieces of a package that we hope Republicans and Democrats can come together around from this podium,” Carney said.

In private, administration aides are similarly coy, though Democratic officials familiar with the discussions say that -- out of precaution -- the party has begun discussing potential addendums to debt ceiling legislation that would be palatable for other party members.

"The triggers that Obama proposed is what is assumed the White House will propose,” said one top Democratic operative briefed on the congressional talks. "The key will be the timing of the triggers. Will they come into affect in two years, five years, ten years?”

In a conference call with reporters on Wednesday, Senate Majority Leader Harry Reid (D-Nev.) announced his support for setting caps on the country’s deficit, either separate from or as a part of legislation raising the debt ceiling.

"If we’re able to cap deficits, it automatically brings down the debt,” he said. "That’s the key to all of this.”

"My personal conviction is that if we have to be able to prove that we're willing to do something about the debt, that we're willing to do something with the deficits, in my opinion we need a deficit cap," Reid added.

It wasn’t entirely clear how those caps would be structured; Reid did little to elaborate during the call. Nor was it clear whether the Majority Leader’s proposal was fundamentally different from the approach that the White House favors: a debt fail-safe that would trigger across the board spending reductions and tax code recalibrations if the ratio of debt-to-GDP doesn’t stabilize over a given period of time.

Reid said he went to the White House in what was an unannounced meeting Tuesday on the debt ceiling. A Senate leadership aide said there was "no firm decision yet” as to what the party would do with either Reid’s or Obama’s proposals, but the political tea leaves point to a deal being cut.